I’d like to offer a few general comments that relate to my own playing and musical interests, that may be helpful to you or stimulating to your thinking about music.
I play with a combination of flesh and nails, and use a thumb pick to give strength to my bass lines. The thumb pick brings ease to my arpeggiation across the strings, and forces my fingers to play with maximum power, to raise the overall volume of the instrument, and thereby to allow for a greater dynamic range in my playing. I find it appealing to play musical phrases “rubato” (with rhythmic flexibility), probably because of my background in a cappella choral singing. Playing freely lets the music breathe, and altering speed, attack and dynamics, as appropriate, help bring drama and urgency to the tune–which helps to maintain the interest of the listener (and the player!)
Here’s a suggestion for your vibrato. Try working the fretted string back and forth across, rather than parallel to, the fingerboard, using only the fretting finger, without the palm or thumb of the left hand as an anchor in back of the guitar neck. Mastering this difficult technique can enhance one’s playing greatly.